ASTM chemical environment test standards

ASTM Chemical Environment Test Standards. Since intergranular corrosion is one of the most serious problems in the satisfactory application of stainless steels, several procedures are available for the measurement of the susceptibility of these steels to this type of corrosion. The procedures have been formalized as standardized tests, designated as ASTM A 262 (Ref 102), and are widely accepted as a basis for certifying that a specific stainless steel meets specifications. A limitation of these tests is that they specify specific environments rather than the environment of the actual application. In many applications, however, reasonable correlations have been established between acceptable response to the tests and successful service performance. 

These test procedures and standards are subject to change, so it is essential to keep up to date if one has to comply with them. It may be possible to obtain the latest issue on a specific test (such as a simple tensile test or a molecular weight test) by contacting the organization that issued it. For example, the ASTM issues new annual standards that include all changes. Their Annual Books of ASTM Standards contain more than seven thousand standards published in sixty-six volumes that include different materials and products. There are four volumes specifically on plastics 08.01-Plastics 1 08.02-Plastics 11 08.03-Plastics III, and 08.04-Plastic Pipe and Building Products. Other volumes include information on plastics and RPs. The complete ASTM index are listed under different categories for the different products, types of tests (by environment, chemical resistance, etc.), statistical analyses of different test data, and so on (56,128,129). 

In applications where possible degrading elements exist, candidate adhesives must be tested under simulated service conditions. Standard lap shear tests, such as ASTM D1002, which use a single rate of loading and a standard laboratory environment, do not yield optimal information on the service life of the joint. Important information such as the maximum load that the adhesive joint will withstand for extended periods and the degrading effects of various chemical environments are addressed by several test methods. Table 15.2 lists common ASTM environmental tests that are often reported in the literature. 

Although published tests such as ASTM C-279 may be used to determine an acid brick s chemical resistance, no standard test exists to predict silica brick behavior. It is necessary to rely on personal experience or to evaluate a brick s performance in a simulated test environment. 

ASTM G109-99a (2005a) Standard Test Method for Determining the Effects of Chemical Admixtures on the Corrosion of Embedded Steel Reinforcement in Concrete Exposed to Chloride Environments. American Society of Testing and Materials, West Conshohocken, PA. 

Finding a Method Various organizations publish volumes of methods for chemical analysis. One of the most well known is the American Society for Testing and Materials, or ASTM. The ASTM is a not-for-profit organization that provides a forum for producers, users, and consumers, to write standards for materials, products, systems, and services. The ASTM (Figure 5.19) publishes standard test methods encompassing metals, paints, plastics, textiles, petroleum, construction, energy, the environment, consumer products, medical services and devices, computerized systems, electronics, and many other areas. More than 10,000 ASTM standards are published each year in the 72 volumes of the Annual Book of ASTM Standards. Individual standards are also available. 

Numbers of service failures began to increase in the 1960s as higher strength alloys were used in a broad range of service applications where high structural performance was desired. Many of the standardized test environments were developed to produce accelerated results that would also rank materials in anticipated service (see footnotes 2-7). The development of new environments and techniques often has been the objective of better correlation with service performance. The most recent of these has been the adoption of ASTM G 123, which has been shown to correlate better with service pierformance of specialty stainless alloys in process chemical application than ASTM G 36, previously widely used. The new standard was developed on completion of an interlaboratory test program [50] that showed better correlation with service performance for the alloys tested. 

It is difficult to compare information between sources. On account of the vagaries of chemical process environments, it is important to develop a database that captures essential information on one s proprietary processes. ASTM standard G 107 [33] may be used as a guide. The amount of information it requires may be daunting. A business should decide what minimum essential elements of corrosion data should be captured in its proprietary corrosion test database. 

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